ValidatorCallout is an ASP.NET AJAX extender that enhances the functionality of existing ASP.NET validators.

ValidatorCallout Properties

Properties

CloseImageUrl - The path to a custom close image

CssClass - Name of the CSS class used to style ValidatorCallout

HighlightCssClass - A CSS class to apply to an invalid field

OnHide - Generic OnHide animation for the ValidatorCallout extender

OnShow - Generic OnShow animation for the ValidatorCallout extender

PopupPosition - Indicates where the ValidatorCallout popup should appear relatively to the control to validate

WarningIconImageUrl - The path to a custom warning icon image

Width - The width of the callout

ValidatorCallout Known Issues

The callouts do not currently display automatically after a server post-back and will only work for
custom validators which utilize client-side validation. Even after a post-back the callout will
display when the form is re-validated when a postback is attempted again.

ValidatorCallout Theming

You can change the look and feel of the ValidatorCallout using the ValidatorCallout CssClass property. The ValidatorCallout
has a predefined set of CSS classes that can be overridden. It has a default style
which is embedded as a WebResource and is a part of the Toolkit assembly that has
styles set for all the sub-classes. You can find the default styles in the Toolkit
solution in the "AjaxControlToolkit\ValidatorCallout\ValidatorCallout.css" file. If your
CssClass does not provide values for any of those then it falls back to the default
value. In the example above the default style is used. To customize the same the
user would have to set the CssClass property to the name of the CSS style and define
the styles for the individual classes so that the various elements in a ValidatorCallout control
can be styled accordingly. For example, if the CssClass property was set to "CustomValidatorCalloutStyle",
this is how the css to style the border and background color would look: